U.S. patent number 4,933,948 [Application Number 07/358,929] was granted by the patent office on 1990-06-12 for dye laser solutions.
This patent grant is currently assigned to Eastman Kodak Company. Invention is credited to William G. Herkstroeter.
United States Patent |
4,933,948 |
Herkstroeter |
June 12, 1990 |
Dye laser solutions
Abstract
Aqueous solutions useful in dye lasers contain a substituted
cyclodextrin-fluorescent dye inclusion compound, and an excess of
the cyclodextrin. Such solutions give greater fluorescent yields
than similar inclusion compounds made from non-substituted
cyclodextrins.
Inventors: |
Herkstroeter; William G.
(Webster, NY) |
Assignee: |
Eastman Kodak Company
(Rochester, NY)
|
Family
ID: |
23411626 |
Appl.
No.: |
07/358,929 |
Filed: |
May 30, 1989 |
Current U.S.
Class: |
372/53;
252/301.17; 8/561; 8/648 |
Current CPC
Class: |
C08B
37/0015 (20130101); C09B 67/0083 (20130101); H01S
3/213 (20130101) |
Current International
Class: |
C08B
37/00 (20060101); C09B 67/00 (20060101); C09B
67/44 (20060101); H01S 3/213 (20060101); H01S
3/14 (20060101); H01S 003/20 (); C09B 067/00 ();
C09B 067/46 (); C09K 011/06 () |
Field of
Search: |
;8/561,408,648
;252/301.17 ;372/53 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Abstract: CA111(12): 105245x, Politzer et al., 1989. .
Abstract: CA107(16): 144715n, Ermanji et al., 1987. .
Abstract: CA103(8): 62125y, Tomaru et al., 1984. .
Abstract: CA101(4): 30990u, Jones et al., 1983. .
Abstract are from Chemical Abstracts of the American Chemical
Society. .
Kobayashi et al., J. of Polymer Science: Part C, Polymer Letters
Edition, vol. 27, pp. 191-195 (May 1989). .
Degani et al., Chemical Physics Letters, vol. 104, No. 5, "Lasing
of Rhodamine B in Aqueous Solutions Containing
.beta.-Cyclodextrin", Feb. 17, 1984, pp. 496-499. .
Agbaria et al., J. Phys. Chem., 92, 1988, pp. 1052-1055. .
Programs and Abstracts of the 17th Northeast Regional Meeting of
the American Chemical Society, Rochester, N.Y., Nov. 8-11, 1987,
Abstract No. 348..
|
Primary Examiner: Clingman; A. Lionel
Assistant Examiner: Darland; Jeff E.
Attorney, Agent or Firm: Linn; Robert A.
Claims
I claim:
1. As a composition of matter, a cyclodextrin inclusion compound of
a fluorescent dye and an .alpha.- or .beta.-chclodextrin having a
substituent bonded to an oxygen atom in a glucose unit in said
cyclodextrin, said substituent being selected from the class
consisting of:
(a) alkyl radicals having 1 to 6 carbon atoms,
(b) radicals having the formula --CH--CHR.sup.1 --O).sub.n H
wherein R.sup.1 is selected from hydrogen and alkyl radicals having
up to about six carbon atoms, and n is equal to a small whole
number up to six, and
(c) radicals having the formula --CHR.sup.1 --CHOH--CHR.sup.1 --
wherein R.sup.1 has the same definition as above, such that said
radicals bridge two cyclodextrin rings, and the number of said
rings so bridged per molecule is from two to about six;
said substituted cyclodextrin having not more than two substituents
per glucose unit.
2. A composition according to claim 1 wherein said cyclodextrin is
a .beta.-cyclodextrin.
3. A composition according to claim 2 wherein said substituent is
an alkyl radical having 1 to six carbon atoms.
4. A composition according to claim 3 wherein the average number of
alkyl radicals per glucose unit is in the range of from about one
to about two.
5. A composition of claim 4 wherein said alkyl radical is a methyl
group.
6. A composition according to claim 2 wherein the cyclodextrin has
a substituent selected from radicals having said formula
7. A composition according to claim 6 wherein the average number of
substituents per glucose unit is in the range of from 1 to about
2.0.
8. A composition according to claim 7 wherein said substituent is
2-hydroxypropyl.
9. A composition according to claim 7 wherein said substituent is
hydroxyethyl.
10. A composition according to claim 2 wherein said substituent has
the formula --CNR.sup.1 --CHON--CHR.sup.1, bridging two
cyclodextrin rings, and the average number of rings so bridged per
molecule of substituted cyclodextrin is from two to about six.
11. An aqueous dye solution for use in a dye laser, said solution
comprising water, an inclusion compound of claim 1, and an excess
of said substituted cyclodextrin such that there is about 1,000
times more non-dye combined cyclodextrin than inclusion
compound.
12. A dye solution of claim 11 wherein the dye concentration is
about 1.times.10.sup.-5 M, and the concentration of the
cyclodextrin is about 0.02M.
13. A dye solution of claim 12 wherein said substituent on said
substituted cyclodextrin is a radical having the formula
--CHR.sup.1 --CHOH--CNR.sup.1 --.
Description
FIELD OF THE INVENTION
This invention relates to aqueous dye solutions useful in dye
lasers. More particularly, it relates to aqueous solutions of
inclusion compounds formed by a cyclodextrin and a fluorescent dye.
The cyclodextrins employed are substituted .alpha. and .beta.
cyclodextrins.
In a particular aspect, this invention relates to the discovery
that substituted cyclodextrin dye inclusion compounds give greater
fluorescent yields than similar compounds formed from
non-substituted cyclodextrins.
BACKGROUND OF THE INVENTION
A laser is a light amplifying apparatus which produces coherent
monochromatic light with excellent directivity. Dye lasers are a
class of liquid lasers. They have an optical resonator comprising a
transparent cell which contains a solution of a laser active dye.
They also comprise a pumping energy source optically coupled to the
cell. During laser operation, the dye solution can be circulated
through a circulation system which includes the cell.
Typical energy pumping sources emit high energy electrons or light.
Discharge tubes, flash lamps, liquid lasers, gas lasers, and solid
lasers can be used as energy pumping units. As a result of their
action, the dye molecules in the dye lasers are excited to higher
energy states causing radiant energy transformation. The light
produced, which travels along the axis of the resonator, is
confined within the resonator for a sufficient period of time to
strongly interact with the excited dye molecules. When the number
of excited dye molecules exceeds the number of molecules in the
ground state, induction emission occurs, and the light is amplified
within the resonator to emit laser light.
One of the major advantages of the dye laser over solid and gas
lasers is its tunability with respect to output wavelengths; that
is, although the laser active dye has a certain range of
fluorescent band, its output wavelengths are accurately controlled
with the aid of a suitable device, such as a prism or a diffraction
grating.
Laser dyes are commonly employed in alcoholic solutions, even
though the thermal properties of water are superior to those of any
alcohol. Specifically, the variation of the refractive index of
water is smaller than that of ethanol. This characteristic is
particularly important for the development of high-power lasers and
for continuous wave lasers.
Aqueous dye solutions have usually not been used in dye lasers
because of low dye solubility and the formation of dye dimers and
higher aggregates. It is most common for dye dimers and aggregates
to form in the H-configuration; such dimers and aggregates usually
show greatly diminished fluorescence quantum yields which are
incompatible with effective lasing. Even for those cases where dye
aggregation does not decrease fluorescence, there are spectral
shifts between dye monomers and dye aggregate to contend with.
Apparently for these reasons, Applicant is unaware of any practical
applications involving dye dimers or higher aggregates in dye
lasers. Thus, a need exists for dye laser aqueous systems which
have enhanced dye solubility and which combat dye dimerization and
higher aggregation. This invention satisfies those needs.
As part of this invention, it has been shown that the presence of a
substituted cyclodextrin increases the water solubility of lasing
dyes. The greater solubility apparently assists in increasing the
fluorescence level, thereby making the system meet the criteria
necessary for effective lasing. This ability of substitution on the
cyclodextrin ring to increase the fluorescence level is unknown in
the art.
As explained more fully below, this invention comprises the use of
substituted cyclodextrins to combat dye aggregation. The synthesis
of chemically modified cyclodextrins is extensively discussed in
Tetrahedron 37, No. 9, pp. 1417-1474 (1983). As stated therein,
cyclodextrins are cyclic oligosaccharides consisting of at least
six glucopyranose units which are joined together by
.alpha.(1.fwdarw.4) linkages. Although cyclodextrins with up to 12
glucose residues are known, only the first three homologs, i.e.,
those having 6, 7, or 8 glucose units, have been studied
extensively. The oligosaccharide ring forms a torus, i.e., a
truncated hollow cone, with the primary hydroxyl groups of the
glucose residues lying on the narrow end of the torus. The
secondary glucopyranose hydroxyl groups are located on the wider
end.
The initial discovery of cyclodextrins is attributed to Villiers,
who isolated them as degradation products of starch. In 1904,
Schardinger demonstrated that these compounds could be obtained by
the action of Bacillus macerans amylase upon starch.
RELATED ART
Degani et al, Chemical Physics Letters Vol. 104, No. 5, 17 Feb.
1984, discusses laser dyes, the use of alcohol and aqueous systems,
and the problem caused by dye aggregation in water. According to
the authors, this difficulty has been dealt with in the past by
adding detergents or using solvent mixtures, leading in fact to
laser action from such modified solutions. The concentrations of
the additives are often in the range of 4-25%, high enough to
adversely affect the superior thermal properties of the aqueous
media.
The authors reported that addition of .beta.-cyclodextrin to
aqueous solutions of rhodamine B results in the deaggregation of
the dye to its monomer form. The deaggregation was attributed to
association of the monomeric rhodamine B to the cyclodextrin.
Agbaria et al, J. Phys. Chem., 1988, 92, 1052-1055 discloses
emulsion complexes of 2,5-diphenyloxazole, a laser dye, and
unsubstituted cyclodextrins.
The Programs and Abstracts of the 17th Northeast Regional Meeting
of the American Chemical Society, Rochester, N.Y., Nov. 8-11, 1987,
includes Abstract No. 348 entitled "Inclusion by Cyclodextrins to
Control Dye Aggregation Equilibria in Aqueous Solution," a paper
given by Applicant and two coworkers, S. Farid and P. A. Martic.
The paper reported that unsubstituted cyclodextrins form inclusion
compounds with oxazine dyes, thereby controllably providing highly
fluorescent monomeric forms.
The references make no suggestion that better fluorescence yields
can be obtained by use of substituted cyclodextrins. Hence,
applicant's discovery of the enhanced effect of substituted
cyclodextrins is a substantial advance in the state of the art.
SUMMARY OF THE INVENTION
This invention relates to the discovery that inclusion compounds of
a fluorescent dye and a substituted cyclodextrin have a greater
ability to overcome the problems of dye aggregation in aqueous
systems than analogous compounds prepared from unsubstituted
cyclodextrins. Stated another way, this invention comprises the
discovery that improvement in relative fluorescent yield is
greater, when a fluorescent dye is bonded to a substituted
cyclodextrin than to an unsubstituted cyclodextrin. Thus, this
invention provides a new type of aqueous fluorescent dye system for
use with dye lasers. More particularly, this invention provides
aqueous dye systems which comprise a substituted cyclodextrin.
Thus, this invention provides a means for enhancing the fluorescent
yield from aqueous fluorescent dyes; viz, the incorporation of a
substituted cyclodextrin in the aqueous system. This invention also
provides improved dye lasers, i.e., lasers comprising the improved
aqueous solutions of the invention.
The cyclodextrins used in this invention have an internal cavity
that is not so large that it can incorporate two or more dye
molecules. Substituted .beta.-cyclodextrins and, in some instances,
substituted .alpha.-cyclodextrins can be used. The latter can be
used when the dye molecule fits within the
.alpha.-cyclodextrin.
As discussed more fully below, this invention comprises use of
cyclodextrins substituted by a hydrophobic group such as an alkyl
group. There is no indication in the literature that the
incorporation of such groups would improve the ability of the
cyclodextrin to combat dye aggregation. Hence, the beneficial
results obtained by this invention are entirely unexpected.
DESCRIPTION OF PREFERRED EMBODIMENTS
This invention provides as a composition of matter, a cyclodextrin
inclusion compound of a fluorescent dye, and an .alpha.- or
.beta.-cyclodextrin having an organic substituent bonded to an
oxygen atom in a ring glucose unit in said cyclodextrin. In said
inclusion compound, there is one dye molecule within each
substituted cyclodextrin ring.
This invention also provides as a composition of matter, an aqueous
system suitable for use in a dye laser, said system comprising (i)
water, (ii) a cyclodextrin inclusion compound of a fluorescent dye
wherein the cyclodextrin is a substituted cyclodextrin having an
organic substituent bonded to a ring glucose unit, and (iii)
ring-substituted cyclodextrin not combined with dye, such that the
relative concentration of the non-dye combined substituted
cyclodextrin in the aqueous medium is substantially higher than the
concentration of the dextrin cyclodextrin inclusion compound. In a
preferred embodiment, there is present in the aqueous medium at
least about 1000 times more non-dye combined substituted
cyclodextrin (S-CD) than substituted cyclodextrin dye inclusion
compound (S-CDDIC). Stated another way, the value of the ratio:
##EQU1## is at least equal to about 100, and is preferably equal to
about 1000. For this calculation, one can assume that the
concentration of (S-CDDIC) is equal to the concentration of dye
added to the medium, and the concentration of substituted
cyclodextrin not bonded in a dye inclusion compound is equal to the
concentration of S-CD added to the water to prepare the dye
solution. By way of illustration, in the examples it is stated that
solutions were prepared wherein the dye concentration is typically
1.times.10.sup.-5 M, and the concentration of the substituted
cyclodextrin used was 0.02M. In such an instance, the above ratio
is calculated as follows: ##EQU2##
It will be recognized that the above calculation is an
approximation. However, it is accurate enough for use in this
invention. In this regard, it is pointed out that better
fluorescent yields are obtained when the concentration of
substituted cyclodextrin is significantly greater than the
concentration of the dye. Without being bound by any theory, it is
believed that there is an equilibrium between dye within the
inclusion compound and dye not within such compounds, and that an
excess of the substituted cyclodextrin favors formation of the
inclusion compound.
It is within the skill of the art for a practitioner, familiar with
this invention, to formulate an aqueous system within the scope of
the invention by preparing a series of solutions having a constant
dye concentration and a varying concentration of substituted
cyclodextrin, and to measure the intensity of fluorescence yield of
each solution, and thereby determine what relative concentration of
dye and cyclodextrin is desirable. Thus, the suggested value range
of ratio (I) above is a guide to defining solutions of this
invention, but routine experimentation of the type suggested above
may indicate that certain solutions within this invention have a
relative concentration ratio outside the suggested range.
The substituted cyclodextrins employed in this invention are
preferably selected from several types of compounds. First, it is
preferred that the cyclodextrin be an .alpha.- or
.beta.-cyclodextrin, i.e., that it have six or seven glucose units
in the ring. More preferably, the substituted cyclodextrin is a
beta cyclodextrin, i.e., it has seven glucopyranose units in the
ring. The substituted alpha dextrins can be used when the dye
molecules are of a sufficient size to fit within the cavity formed
by the ring of glucopyranose units. Second, it is preferred that
the substituent or substituents in the cyclodextrin molecules be
bonded to an oxygen atom in a ring glucose unit. It is also
preferred that when the cyclodextrin has two or more substituents
per molecule, the substituents be the same. Such compounds are
preferred because they are more generally available; however, it is
to be understood that this invention is not limited to their
use.
Each glucose unit may have a substituent; however, it is not
necessary that the cyclodextrin be that heavily substituted. In
other words, not all of the ring glucose units need to be
substituted. For this invention, it is only necessary that on
average, each cyclodextrin molecule has one substituent per dextrin
ring. The substituents may be in one or more of the 2-, 3-, or
6-positions in the glucopyranose rings.
The cyclodextrin rings may be composed of glucose units (sometimes
referred to herein as glucopyranose units) having up to three
substituents. Again, it is not necessary that the units be that
heavily substituted. Hence, it is preferred that the number of
substituents per glucose unit be within the range of from about 0.5
to about 2.0. It is to be understood that the invention extends to
the use of cyclodextrins somewhat outside this range. Thus, for
example, one may use hexakis and heptakis tri-substituted
compounds; i.e., .alpha.- and .beta.-cyclodextrins having three
substituents per glucose unit.
Compounds of the types discussed above have preferred types of
substituents. One preferred type of substituent is an alkyl
radical. Of the alkyl radicals, those having up to about six carbon
atoms are preferred. The methyl group is a highly preferred
substituent, especially when two or more substituents are on one
glucose unit in the dextrin ring.
A second preferred type of substituent has the formula
--(CH--CHR.sup.1 --O--).sub.n --H wherein R.sup.1 is selected from
the class consisting of hydrogen and alkyl groups having up to
about six carbon atoms. In the above formula, n is a small whole
number having a value up to about six; preferably, n is equal to 1.
Preferred substituents of this type are hydroxyethyl and
hydroxypropyl.
A third type of substituent on the cyclodextrin is a bridging group
that links two cyclodextrin moieties. These bridging groups have
the formula --CHR.sup.1 --CHOH--CHR.sup.1 -- wherein R.sup.1 has
the same significance as above. In these polymeric cyclodextrins,
the number of cyclodextrin rings so bridged is from two to about
six. In other words, there can be two cyclodextrin rings linked by
the bridging group, or there can be three of the rings linked by
two bridging groups, and so on, such that there can be six rings
linked by five bridging groups. It is to be understood that higher
polymers can be used in the invention if they have properties
analogous to the polymers within the range given above, and the
increased size or molecular weight does not confer an undesirable
property to the extent that it makes the material unsuitable for
use in the invention.
The polymeric cyclodextrins may have substituents in addition to
the group that links or bridges two cyclodextrin moieties. For
example, the cyclodextrin moieties may have one or more
carboxyalkyl (--R--COOH) substituents, wherein R is a lower
alkylene radical having up to about 4 carbon atoms. Preferably such
a substituent is carboxymethyl; --CH.sub.2 --COOH. Preferably,
there are two carboxymethyl groups per cyclodextrin ring.
In a preferred embodiment, the dye and the substituted cyclodextrin
are added to water at or about their limit of solubility. Although
one can employ more dilute systems, concentrated materials
generally give better results. In general, the dyes are much less
soluble than the substituted cyclodextrins. It has also been
observed that the substituted cyclodextrins used in this invention
quite often have greater water solubility than unsubstituted
cyclodextrins. In a preferred embodiment, the substituted materials
have an enhanced water solubility compared to the unsubstituted
materials.
This invention is not limited to the use of any particular class of
fluorescent dyes. In other words, the dye from which the inclusion
compound is made can be selected from a wide range of materials. Of
the fluorescent dyes, the following types can be mentioned.
One preferred class of fluorescent dyes are fluorescent coumarin
dyes. Among specifically preferred fluorescent coumarin dyes are
those satisfying formula I: ##STR1## where R.sup.1 is chosen from
the group consisting of hydrogen, carboxy, alkanoyl,
alkoxycarbonyl, cyano, aryl, and a heterocylic aromatic group,
R.sup.2 is chosen from the group consisting of hydrogen, alkyl,
haloalkyl, carboxy, alkanoyl, and alkoxycarbonyl,
R.sup.3 is chosen from the group consisting of hydrogen and
alkyl,
R.sup.4 is an amino group, and
R.sup.5 is hydrogen, or
R.sup.1 and R.sup.2 together form a fused carbocyclic ring,
and/or
the amino group forming R.sup.5 completes with at least one of
R.sup.4 and R.sup.6 a fused ring.
The alkyl moieties in each instance contain from 1 to 5 carbon
atoms, preferably 1 to 3 carbon atoms. The aryl moieties are
preferably phenyl groups. The fused carbocyclic rings are
preferably five, six, or seven membered rings. The heterocyclic
aromatic groups contain 5 or 6 membered heterocyclic rings
containing carbon atoms and one or two heteroatoms chosen from the
group consisting of oxygen, sulfur, and nitrogen. The amino group
can be a primary, secondary, or tertiary amino group. When the
amino nitrogen completes a fused ring with an adjacent substituent,
the ring is preferably a five or six membered ring. For example,
R.sup.5 can take the form of a pyran ring when the nitrogen atom
forms a single ring with one adjacent substituent (R.sup.3 or
R.sup.5) or a julolidine ring (including the fused benzo ring of
the coumarin) when the nitrogen atom forms rings with both adjacent
substituents R.sup.3 and R.sup.5.
The following are illustrative fluorescent coumarin dyes known to
be useful as laser dyes:
______________________________________ FD 1
7-Diethylamino-4-methylcoumarin FD 2
4,6-Dimethyl-7-ethylaminocoumarin FD 3 4-Methylumbelliferone FD 4
3-(2-Benzothiazolyl)-7-diethylaminocoumarin FD 5
3-(2'-Benzimidazolyl)-7-N,N-diethylamino coumarin FD 6
7-Amino-3-phenylcoumarin FD 7
3-(2'-N-Methylbenzimidazolyl)-7-N,Ndiethyl- aminocoumarin FD 8
7-Diethylamino-'-4-trifluoromethylcoumarin FD 9 2,3,5,6-
lH'-4H-Tetrahydro-8-methylquinola zino[9,9a,1 -gh]coumarin FD 10
Cyclopenta[c]Julolindino[9,10 3]llH-pyran 11 one FD 11
7-Amino-4-methylcoumarin FD 12 7-Dimethylaminocyclopenta[c]coumarin
FD 13 7-Amino-4-trifluoromethylcoumarin FD 14
7-Dimethylamino-4-trifluoromethylcoumarin FD 15
1,2,4,5,3H,6H,10H-Tetrahydro-8-trifluoro
methyl[1]benzopyrano[9,9a,l gh]quinolizin 10 one FD 16
4-Methyl-7-(sulfomethylamino)coumarin sodium salt FD 17
7-Ethylamino-6-methyl-trifluoromethylcou- marin FD 18
7-Dimethylamino-4-methylcoumarin FD 19
1,2,4,5,3H,6H,10H-Tetrahydro-carbethoxy [1]benzopyrano[9,9a,l
gh]quinolizino-10-one FD 20 9-cetyl-1,2,4,5.3H,6H.10H-tetrahydro[1]
benzopyrano[9.9a.1 h]quinolizino-10-one FD 21
9-Cyano-1,2,4,5,3H,6H,10H-tetrahydro[1] benzopyrano[9.9a,l
h]quinolizino-10-one FD 22 9-( Butoxycarbonyl)-1,2,4,5,3H,6H,10H
tetrahyro[1]benzopyrano[9,9a,l gh]quino lizino-10-one FD 23
4-MethylPiPeridino[3.2 g]coumarin FD 24
4-Trifluoromethylpiperidino[3.2 ]coumarin FD 25
9-Carboxy-1,2,4,5,3H,6H,10H-tetrahydro1] benzopyrano9.9a[40 -l
h]quinolizino-10-one FD 26 N-Ethyl-4-trifluoromethylpiperidino[3,2
] coumarin ______________________________________
Another preferred class of fluorescent dyes are fluorescent
4-dicyanomethylene-4H-pyrans and 4-dicyanomethylene-4H-thiopyrans,
hereinafter referred to as fluorescent dicyanomethylenepyran and
thiopyran dyes. Preferred fluorescent dyes of this class are those
satisfying formula (II): ##STR2## wherein X represents oxygen or
sulfur;
R.sup.6 represents a 2-(4-aminostyryl) group; and
R.sup.7 represents a second R.sup.6 group, an alkyl group, or an
aryl group.
Although X most conveniently represents oxygen or sulfur, it is
appreciated that higher atomic number chalcogens should provide
similar, though bathochromically shifted, response. The amino group
can be a primary, secondary, or tertiary amino group. In one
specifically preferred form the amino group can form at least one
additional fused ring with the styryl phenyl ring. For example, the
styryl phenyl ring and the amino group can together form a
julolidine ring or the amino group can form an five or six membered
ring fused with the styryl phenyl ring. The alkyl group forming
R.sup.6 typically contains from 1 to 5 carbon atoms, preferably 1
to 3 carbon atoms. The aryl group forming R.sup.6 is preferably
phenyl. When both R.sup.6 and R.sup.7 form a 2-(4-aminostyryl)
group, the groups can be the same or different, but symmetrical
compounds are more conveniently synthesized.
The following are illustrative fluorescent dicyanomethylenepyran
and thiopyran dyes:
______________________________________ FD-27
4-(Dicyanomethylene)-2-methyl-6-( -p-di-
methylaminostyryl)-4H-pyran FD-28
4-(Dicyanomethylene)-2-methyl-6-[2-(9- julolidyl)ethenyl]-4H-pyran
FD-29 4-(Dicyanomethylene)-2-phenyl-6-[2-(9-
julolidyl)ethenyl]-4H-pyran FD-30
4-(Dicyanomethylene)2,6-[2-(9-julo- lidyl)ethenyl]-4H-pyran FD-31
4-(Dicyanomethylene)-2-methyl-6-[2-(9-
julolidyl)ethenyl]-4H-thiopyran
______________________________________
Useful fluorescent dyes can also be selected from among known
polymethine dyes, which include the cyanines, merocyanines, complex
cyanines and merocyanines (i.e., tri-, tetra- and poly-nuclear
cyanines and merocyanines), oxonols, hemioxonols, styryls,
merostyryls, and streptocyanines.
The cyanine dyes include, joined by a methine linkage, two basic
heterocyclic nuclei, such as azolium or azinium nuclei, for
example, those derived from pyridinium, quinolinium,
isoquinolinium, oxazolium, thiazolium, selenazolium, indazolium,
pyrazolium, pyrrolium, indolium, 3H-indolium, imidazolium,
oxadiazolium, thiadioxazolium, benzoxazolium, benzothiazolium,
benzoselenzolium, benzotellurazolium, benzimidazolium, 3H- or
1H-benzoindolium, naphthoxazolium, naphthothiazolium,
naphthoselenazolium, naphthotellurazolium, carbazolium,
pyrrolopyridinium, phenanthrothiazolium, and acenaphthothiazolium
quaternary salts.
Exemplary of the basic heterocyclic nuclei are those satisfying
Formulae III and IV. ##STR3## where Z.sup.3 represents the elements
needed to complete a cyclic nucleus derived from basic heterocyclic
nitrogen compounds such as oxazoline, oxazole, benzoxazole, the
naphthoxazoles (e.g., naphth[2,1-d]oxazole, naphth[2,3-d]oxazole,
and naphth[1,2-d]oxazole), oxadiazole, thiazoline, thiazole,
benzothiazole, the naphthothiazoles (e.g., naphtho[2,1-d]thiazole),
the thiazoloquinolines (e.g., thiazole[4,5-b]quinoline),
phenanthrothiazole, acenaphthothiazole, thiadioxazole,
selenazoline, selenazole, benzoselenazole, the naphthoselenazoles
(e.g., naphtho[1,2-d]selenazole), benzotellurazole,
naphthotellurazoles (e.g., naptho[1,2-d]tellurazole), imidazoline,
imidazole, benzimidazole, the naphthimidazoles (e.g.,
naphth[2,3-d]imidazole), 2- or 4-pyridine, 2- or 4-quinoline, 1- or
3-isoquinoline, benzoquinoline, 3H-indole, 1H- or 3H-benzoindole,
and pyrazole, which nuclei may be substituted on the ring by one or
more of a wide variety of substituents such as hydroxy, the
halogens (e.g., fluoro, chloro, bromo, and iodo), alkyl groups or
substituted alkyl groups (e.g., methyl, ethyl, propyl, isopropyl,
butyl, octyl, dodecyl, octadecyl, 2-hydroxyethyl, 3-sulfopropyl,
carboxymethyl, 2-cyanoethyl, and trifluoromethyl), aryl groups or
substituted aryl groups (e.g., phenyl, 1-naphthyl, 2-naphthyl,
4-sulfophenyl, 3-carboxyphenyl, and 4-biphenylyl), aralkyl groups
(e.g., benzyl and phenethyl), alkoxy groups (e.g., methoxy, ethoxy,
and isopropoxy), aryloxy groups (e.g., phenoxy and 1-naphthoxy),
alkylthio groups (e.g., methylthio and ethylthio), arylthio groups
(e.g., phenylthio, p-tolylthio, and 2-naphthylthio),
methylenedioxy, cyano, 2-thienyl, styryl, amino or substituted
amino groups (e.g., anilino, dimethylamino, diethylamino, and
morpholino), acyl groups, (e.g., formyl, acetyl, benzoyl, and
benzenesulfonyl);
Q' represents the elements needed to complete a cyclic nucleus
derived from basic heterocyclic nitrogen compounds such as pyrrole,
indole, carbazole, benzindole, pyrazole, indazole, and
pyrrolopyridine;
R represents alkyl groups, aryl groups, alkenyl groups, or aralkyl
groups, with or without substituents, (e.g., carboxy, hydroxy,
sulfo, alkoxy, sulfato, thiosulfato, phosphono, chloro, and bromo
substituents);
L is in each occurrence independently selected to represent a
substituted or unsubstituted methine group--e.g., --CR.sup.8 .dbd.
groups, where R.sup.8 represents hydrogen when the methine group is
unsubstituted and most commonly represents alkyl of from 1 to 4
carbon atoms or phenyl when the methine group is substituted;
and
q is 0 or 1.
Cyanine dyes can contain two heterocyclic nuclei of the type shown
in Formula III joined by a methine linkage containing an uneven
number of methine groups or can contain a heterocyclic nucleus
according to each of Formulae III and IV joined by a methine
linkage containing an even number of methine groups, where the
methine groups can take the form --CR.sup.8 .dbd. as described
above. The greater the number of the methine groups linking nuclei
in the polymethine dyes in general and the cyanine dyes in
particular the longer the absorption wavelengths of the dyes. For
example, dicarbocyanine dyes (cyanine dyes containing five methine
groups linking two basic heterocyclic nuclei) exhibit longer
absorption wavelengths than carbocyanine dyes (cyanine dyes
containing three methine groups linking two basic heterocyclic
nuclei) which in turn exhibit longer absorption wavelengths than
simple cyanine dyes (cyanine dyes containing a single methine group
linking two basic heterocyclic nuclei). Carbocyanine and
dicarbocyanine dyes are longer wavelength dyes while simple cyanine
dyes are typically yellow dyes, but can exhibit absorption maxima
up to about 550 nm in wavelength with proper choice of nuclei and
other components capable of bathochromically shifting
absorption.
Preferred polymethine dyes, particularly cyanine dyes, for use as
fluorescent dyes are so-called regidized dyes. These dyes are
constructed to restrict the movement of one nucleus in relation to
another. This avoids radiationless, kinetic dissipation of the
excited state energy. One approach to rigidizing the dye structure
is to incorporate a separate bridging group providing a separate
linkage in addition to the methine chain linkage joining the
terminal nuclei of the dye. Bridged polymethine dyes are
illustrated by Brooker et al U.S. Pat. No. 2,478,367, Brooker U.S.
Pat. No. 2,479,152, Gilbert U.S. Pat. No. 4,490,463, and Tredwell
et al, "Picosecond Time Resolved Fluorescence Lifetimes of the
Polymethine and Related Dyes", Chemical Physics, Vol. 43 (1979) pp.
307-316.
The methine chain joining polymethine dye nuclei can be rigidized
by including the methine chain as part of a cyclic nucleus joining
the terminal basic nuclei of the dye. One of the techniques for
both rigidizing and bathochromically shifting the absorption maxima
of polymethine dyes in general and cyanine dyes in particular is to
include in the methine linkage an oxocarbon bridging nucleus.
Exemplary oxocarbon bridging nuclei can take any of the forms
indicatd by Formula V. ##STR4## wherein n is the integer 0, 1, or
2.
Merocyanine dyes link one of the cyanine dye type basic
heterocyclic nuclei described above to an acidic keto methylene
nucleus through a methine linkage as described above, but
containing zero, two, or a higher even number of methine groups.
Zero methine dyes, those containing no methine groups in the
linkage between nuclei, exhibit a double bond linkage between the
nuclei in one resonance form and a single bound linkage in another
resonance form. In either resonance form the linkage sites in the
nuclei are formed by methine groups forming a part of each nucleus.
Zero methine polymethine dyes are yellow dyes..
Exemplary acidic nuclei are those which satisfy Formula VI.
##STR5## where G.sup.1 represents an alkyl group or substituted
alkyl group, an aryl or substituted aryl group, an aralkyl group,
an alkoxy group, an aryloxy group, a hydroxy group, an amino group,
or a substituted amino group, wherein exemplary substituents can
take the various forms noted in connection with Formulae VI and
VII;
G.sup.2 can represent any one of the groups listed for G.sup.1 and
in addition can represent a cyano group, an alkyl, or arylsulfonyl
group, or a group represented by ##STR6## or G.sup.2 taken together
with G.sup.1 can represent the elements needed to complete a cyclic
acidic nucleus such as those derived from 2,4-oxazolkidinone (e.g.,
3-ethyl-2,4-oxazolidindione), 2,4-thiazolidindione (e.g.,
3-methyl-2,4-thiazolidindione), 2-thio-2,4-oxazolidindione (e.g.,
3-phenyl-2-thio-2,4-oxazolidindione), rhodanine, such as
3-ethylrhodanine, 3-phenylrhodanine,
3-(3-dimethylaminopropyl)rhodanine, and 3-carboxymethylrhodanine,
hydantoin (e.g., 1,3-diethylhydantoin and
3-ethyl-1-phenylhydantoin), 2-thiohydantoin (e.g.,
1-ethyl-3-phenyl-2-thiohydantoin,
3-heptyl-1-phenyl-2-thiohydantoin, and
arylsulfonyl-2-thiohydantoin), 2-pyrazolin-5-one, such as
3-methyl-1-phenyl-2-pyrazolin-5-one,
3-methyl-1-(4-carboxybutyl)-2-pyrazolin-5-one, and
3-methyl-2-(4-sulfophenyl)-2-pyrazolin-5-one, 2-isoxazolin-5-one,
(e.g., 3-phenyl-2-isoxazolin-5-one), 3,5-pyrazolidindione (e.g.,
1,2-diethyl-3,5-pyrazolidindione and
1,2-diphenyl-3,5-pyrazolidindione), 1,3-indandione,
1,3-dioxane-4,6-dione, 1,3-cyclohexanedione, barbituric acid (e.g.,
1-ethylbarbituric acid and 1,3-diethylbarbituric acid), and
2-thiobarbituric acid (e.g., 1,3-diethyl-2-thiobarbituric acid and
1,3-bis(2-methoxyethyl)-2-thiobarbituric acid).
Useful hemicyanine dyes are essentially similar to the merocyanine
dyes described above, differing only in substituting for the keto
methylene group of Formula VI the group shown below in Formula VII.
##STR7## where G.sup.3 and G.sup.4 may be the same or different and
may represent alkyl, substituted alkyl, aryl, substituted aryl, or
aralkyl, as illustrated for ring substituents in Formula VI or
G.sup.3 and G.sup.4 taken together complete a ring system derived
from a cyclic secondary amine, such as pyrrolidine, 3-pyrroline,
piperidine, piperazine (e.g., 4-methylpiperazine and
4-phenylpiperazine), morpholine, 1,2,3,4-tetrahydroquinoline,
decahydroquinoline, 3-azabicyclo[3,2,2]nonane, indoline, azetidine,
and hexahydroazepine.
Useful hemioxonol dyes exhibit a keto methylene nucleus as shown in
Formula VI and a nucleus as shown in Formula VII joined by a
methine linkage as previously described containing one or a higher
uneven number of methine groups.
Useful merostyryl dyes exhibit a keto methylene nucleus as shown in
Formula VI and a nucleus as shown in Formula VIII joined by a
methine linkage as described above containing one or a higher
uneven number of methine groups. ##STR8## where G.sup.3 and G.sup.4
are as previously defined.
The longer wavelength cyanine, merocyanine, hemicyanine,
hemioxonol, and merostyryl dyes described above are intended to be
illustrative of the simpler structural forms of useful longer
wavelength polymethine dyes. It is generally recognized that
substituents can join the nuclei and methine linkages to form
additional cyclic structures. Further, the dyes can contain three
or more nuclei. For example, by substituting a merocyanine dye in
methine linkage with a second basic heterocyclic nucleus of the
cyanine dye type an allopolar cyanine dye can be formed. Further,
the various substituents not forming a part of the dye chromophore
can be varied as desired to tailor dye physical properties,
particularly hydrophobicity and hydrophillicity, to suit the
particular film forming components employed. By choosing as the
aliphatic moieties of the dyes hydrocarbon groups having more
carbon atoms (e.g., from about 6 to 20 carbon atoms) the dyes can
be rendered more oleophilic while hydrocarbon groups containing
fewer numbers of carbon atoms (e.g., 1 to 5 carbon atoms) and
particularly those bearing polar substituents render the dyes more
hydrophilic. The aromatic moieties of the dyes typically contain
from 6 to 10 carbon atoms.
The following are illustrative of polymethine dyes capable of
maximum light absorption at shorter (<550 nm) wavelengths:
__________________________________________________________________________
##STR9## X.sup.- R X.sup.-
__________________________________________________________________________
FD-32 C.sub.16 H.sub.33 Cl.sup.- FD-33 C.sub.18 H.sub.37 PTS.sup.-
FD-34 CH.sub.2 CHCH.sub.2 Cl.sup.- PTS = -p-toluene sulfonate FD-35
##STR10## Cl.sup.- FD-36 ##STR11## Cl.sup.- ##STR12## X.sup.- R
X.sup.-
__________________________________________________________________________
FD-37 CH.sub.2 CH.sub.3 ClO.sub.4.sup.- FD-38 C.sub.4 H.sub.9
ClO.sub.4.sup.- FD-39 C.sub.5 H.sub.11 BF.sub.4.sup.- FD-40
##STR13## Cl.sup.- FD-41 ##STR14## ClO.sub.4.sup.- FD-42 ##STR15##
ClO.sub.4.sup.- FD-43 ##STR16## Cl.sup.- ##STR17## C1.sup.- R.sup.a
R R.sup.b
__________________________________________________________________________
FD-44 CH.sub.3 CH.sub.3 H FD-45 CH.sub.3 CH.sub.3 C.sub.2 H.sub.3
FD-46 C.sub.3 H.sub.7 CH.sub.3 H FD-47 ##STR18## I.sup.- ##STR19##
X.sup.- n R R.sup.c X.sup.-
__________________________________________________________________________
FD-48 1 CH.sub.3 C.sub.2 H.sub.5 PTS.sup.- FD-49 1 (CH.sub.2).sub.3
SO.sub.3.sup.- C.sub.5 H.sub.11 -- FD-50 1 (CH.sub.2).sub.4
SO.sub.3.sup.- C.sub.5 H.sub.11 -- FD-51 2 (CH.sub.2).sub.5
SO.sub.3.sup.- C.sub.2 H.sub.5 -- FD-52 3,3'-Ethylenethiacyanine
-p-toluenesulfonate FD-53 1',3-Ethylenethia-2'-cyanine chloride
FD-54 1,1'-Ethylene-2,2'-cyanine chloride FD-55
3,3'-Ethyleneoxacyanine chloride FD-56
1,1'-Diethyl-3,3'-Ethylenebenzimidazolocyanine -p-toluenesulfonate
FD-57 1,1'-Diethyl-3,3'-methylenebenzimidazolocyanine chloride
FD-58 1,1'-Ethylenecyanine chloride FD-59 1,1'-Methylenecyanine
chloride FD-60 5,5',6,6'-Tetrachloro-1,1'-diethyl-3,3'-
ethanediylbenzimidazolocyanine chloride FD-61
5,5',6,6'-Tetrachloro-1,1'-ethanediyl-3,3'-
dimethylbenzimidazolocyanine chloride FD-62
Anhydro-5,5',6,6'-tetrachloro-1,1'
-ethan-diyl-3,3'-bis(3-sulfopropyl) - benzimidazolo-cyanine
hydroxide, sodium salt FD-63
2,2'-Methanediylbis-(5,6-dichloro-1-methylbenzimidazole FD-64
5,5',6,6'-Tetrachloro-1,1'-dimethyl-3,3'-
propanediylbenzimidazolocyanine -p-toluenesulfonate FD-65
5,5',6,6'-Tetrachloro-1,1'-dimethyl-3,3'-
methanediylbenzimidazolocyanine -p-toluenesulfonate FD-66
5,5',6,6'-Tetrachloro-1,1'-ethanediyl-3,3'-
bis(2,2,2-trifluoroethyl)benzimidazolocyanine -p-toluenesulfonate
FD-67 5,5',6,6'-Tetrachloro-1,1'-ethanediyl-
3,3',8-trimethylbenzimidazolocyanine -p-toluenesulfonate
__________________________________________________________________________
Many polymethine dyes are capable of maximum light absorption at
longer visible (>550 nm) wavelengths, with maximum fluorescence
wavelengths generally lying in the red and near infrared portions
of the spectrum. The following are illustrative of polymethine dyes
capable of maximum light absorption at longer visible
wavelengths:
__________________________________________________________________________
##STR20## n R.sup.d X.sup.-
__________________________________________________________________________
FD-68 1 -- BF.sub.4.sup.- FD-69 2 -- PTS.sup.- FD-70 3 --
BF.sub.4.sup.- FD-71 3 ##STR21## ClO.sub.4.sup.- FD-72 ##STR22##
FD-73 ##STR23## FD-74 ##STR24## FD-75 ##STR25##
__________________________________________________________________________
##STR26## R R.sup.8 R.sup.e X.sup.-
__________________________________________________________________________
FD-76 C.sub.4 H.sub.9 H -- Cl.sup.- FD-77 C.sub.18 H.sub.37 H --
PTS.sup.- FD-78 C.sub.4 H.sub.9 CH.sub.3 -- Cl.sup.- FD-79 C.sub.5
H.sub.11 CH.sub.3 -- Cl.sup.- FD-80 i-C.sub.3 H.sub.7 CH.sub.3 --
Cl.sup.- FD-81 C.sub.3 H.sub.7 C.sub.2 H.sub.5 -- Cl.sup.- FD-82
C.sub.2 H.sub.5 C.sub.2 H.sub.5 -- C.sub.3 F.sub.7 COO.sup.- FD-83
C.sub.2 H.sub.5 C.sub.6 H.sub.11 ##STR27## Cl.sup.- (cyclohexyl)
FD-84 C.sub.2 H.sub.5 C.sub.15 H.sub.31 ##STR28## Cl.sup.-
__________________________________________________________________________
##STR29## R R.sup.8a R.sup.8b R.sup.8c R.sup.8d R.sup.f X.sup.-
__________________________________________________________________________
FD-85 CH.sub.2 CH.sub.3 H H H H H Cl.sup.- FD-86 CH.sub.2 CH.sub.3
H H H H OCH.sub.3 PTS.sup.- FD-87 CH.sub.2 CH.sub.3 H H H CH.sub.3
H ClO.sub.4.sup.- FD-88 CH.sub.2 CH.sub.3 H ##STR30## H H
ClO.sub.4.sup.- FD-89 ##STR31## H H H H PTS.sup.- FD-90 ##STR32##
##STR33## H H PTS.sup.- FD-91 ##STR34## FD-92 ##STR35## FD-93
##STR36## FD-94 ##STR37## FD-95 ##STR38##
__________________________________________________________________________
##STR39## R X.sup.-
__________________________________________________________________________
FD-96 CH.sub.2 CH.sub.2 C.sub.6 H.sub.5 BF.sub.4.sup.- FD-97
CH.sub.2 CH.sub.3 Cl.sup.- FD-98 ##STR40## FD-99 ##STR41## FD-100
##STR42## FD-101 ##STR43## FD-102 ##STR44##
__________________________________________________________________________
##STR45## R.sup.h R R.sup.g
__________________________________________________________________________
FD-103 CH.sub.3 CH.sub.3 -- FD-104 CH.sub. 3 CH.sub.3 ##STR46##
FD-105 CH.sub.3 C.sub.6 H.sub.5 -- FD-106 CH.sub.3 ##STR47## --
FD-107 ##STR48## FD-108 ##STR49##
__________________________________________________________________________
##STR50##
__________________________________________________________________________
FD-109 R = C.sub.6 H.sub.5 FD-110 R = C.sub.10 H.sub.7, i.e. -
.alpha.-naphthyl FD-111 ##STR51## FD-112 ##STR52## FD-113 ##STR53##
__________________________________________________________________________
Another useful class of fluorescent dyes are
4-oxo-4H-benz-[d,e]anthracenes, hereinafter referred to as
oxobenzanthracene dyes. Dyes of this class and their preparations
are disclosed in Goswami et al U.S. Pat. No. 4,812,393. Preferred
fluorescent oxobenzanthracene dyes are those represented by Formula
IX: ##STR54##
In this structure, R.sup.9 is hydrogen, substituted or
unsubstituted alkyl (preferably of 1 to 12 carbon atoms, e.g.
methyl, ethyl, isopropyl, benzyl, phenethyl, etc.), substituted or
unsubstituted hydroxyalkyl (preferably of 1 to 12 carbon atoms,
e.g. hydroxymethyl, 2-hydroxyethyl, 2-hydroxyisopropyl, etc.), or
substituted or unsubstituted alkoxycarbonyl (preferably of 2 to 12
carbon atoms, e.g. methoxycarbonyl, ethoxycarbonyl,
n-propoxycarbonyl, etc.). Preferably, R.sup.9 is hydrogen,
substituted or unsubstituted alkyl or substituted or unsubstituted
alkoxycarbonyl, and more preferably, it is substituted or
unsubstituted alkoxycarbonyl.
W is hydrogen or an electron withdrawing group as that term is
understood in the art (i.e. a group generally having a positive
Hammett sigma value as determined by standard procedures).
Particularly useful electron withdrawing groups include, but are
not limted to, halo (e.g. fluoro, chloro, bromo), cyano, carboxy,
acyl, substituted or unsubstituted arylsulfonyl (preferably of 6 to
10 carbon atoms, e.g. phenylsulfonyl, tolylsulfonyl, etc.),
substituted or unsubstituted alkylsulfonyl (preferably of 1 to 6
carbon atoms, e.g. methylsulfonyl, ethylsulfonyl, etc.),
substituted and unsubstituted dialkylphosphinyl (preferably where
each alkyl group independently has 1 to 10 carbon atoms, e.g.
methyl, ethyl, butyl, decyl, etc.) and substituted or unsubstituted
dialkyl phosphono (preferably where each alkyl group independently
has 1 to 10 carbon atoms as defined above). Preferably, W is
hydrogen or halo.
Y.sup.1 is hydrogen, or a group comprised of a heteroatom having a
lone pair of electrons or a negative charge with an associated
cation, e.g. hydroxy, mercapto or amino (--NR"R"'). R" and R"' are
independently substituted or unsubstituted alkyl (preferably of 1
to 10 carbons, e.g., methyl, ethyl, decyl, etc.), substituted or
unsubstituted aryl (preferably of 6 to 10 carbons, e.g., phenyl,
naphthyl, etc.), or R" and R"', taken together, can represent the
atoms necessary to complete a subsituted or unsubstituted
heterocyclic ring (preferably of 5 to 10 carbon, nitrogen or oxygen
atoms, e.g. a morpholino, pyrrolidinyl, pyridyl, piperidino, etc.
ring). Y.sup.1 can also be substituted or unsubstituted alkoxy
(preferably of 1 to 10 carbon atoms, e.g. methoxy, ethoxy,
2-chloro-1-propoxy, etc.), substituted or unsubstituted carbamyloxy
##STR55## wherein R" and R"' are defined above, --O.sup.- M.sup.+
or --S.sup.- M.sup.+, wherein M.sup.+ is a monovalent cation, e.g.
Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, etc. Preferably
Y.sup.1 is hydroxy or --O.sup.-M.sup.+.
______________________________________ R.sup.9 W Y.sup.1
______________________________________ FD-114 Methyl Hydrogen
Hydroxy FD-115 Methyl Hydrogen --O.sup.- Na.sup.+ FD-116 Methyl
Chloro Hydroxy FD-117 Methyl Chloro --O.sup.- Na.sup.+ FD-118
Methyl Chloro N-methyl-N- phenylcarbamyloxy FD-119 Methyl Hydrogen
Pyrrolidinyl FD-120 Butoxy- Hydrogen Hydroxy carbonyl FD-121
Butoxy- Hydrogen --O.sup.- Na.sup.+ carbonyl FD-122 Butoxy- Chloro
--O.sup.- Na.sup.+ carbonyl
______________________________________
The oxobenzanthracene dyes illustrated above can have one or more
substituents other than those specifically illustrated in the
structure as long as the substituents do not adversely affect the
fluorescence of the compound, such as alkyl (e.g., alkyl of 1 to 5
carbon atoms), aryl (e.g., phenyl), and other groups.
The oxobenzanthracene dyes can be prepared generally using the
following procedure. The general preparatory procedure includes:
(1) preparation of a dihydrophenalenone by the procedure described
by Cooke et al, Australian J. Chem., 11, pp. 230-235 (1958), (2)
preparation of the lithium enolate of the dihydrophenalenone, (3)
reaction of the lithium enolate with the appropriate phosphonium
iodide reagent, and (4) reaction of this product with cupric
chloride and lithium chloride to produce the chlorinated or
unchlorinated dye.
Another useful class of fluorescent dyes are xanthene dyes. One
particularly preferred class of xanthene dyes are rhodamine dyes.
Preferred fluorescent rhodamine dyes are those represented by
Formula X: ##STR56## where R.sup.10 and R.sup.11 are independently
hydrogen, carboxyl, sulfonyl, alkanoyl, or alkoxycarbonyl
groups;
R.sup.12, R.sup.13, R.sup.14, and R.sup.15 are hydrogen;
R.sup.16, R.sup.17, R.sup.18, and R.sup.19 are alkyl groups;
and
X.sup.- is an anion; or
any one of or all of following substituent pairs: R.sup.12 and
R.sup.16, R.sup.13 and R.sup.17, R.sup.14 and R.sup.18, and
R.sup.15 and R.sup.19, complete a five or six membered ring
containing nitrogen as the sole heteroatom.
The alkyl moieties in each instance contain from 1 to 5 carbon
atoms, preferably 1 to 3 carbon atoms. When substituent pairs
complete a fused ring, the ring can, for example, take the form of
a pyran ring when a single fused ring including a formula nitrogen
atom is formed or a julolidene ring (including a formula fused
benzo ring) when two fused rings each including the same nitrogen
atom of the formula are formed.
The following are illustrative of rhodamine dyes known to be useful
laser dyes:
______________________________________ FD-123 [9-(
-o-Carboxyphenyl)-6-(diethylamino)-3H- xanthen-3-ylidene]diethyl
ammonium chloride [a.k.a rhodamine B] FD-124
N-{6-[Diethylamino]-9-[2-(ethoxycarbon-
yl)-phenyl]-3H-xanthen-3-ylidene}-N- ethylethanaminium perchlorate
FD-125 Ethyl -o-[6-(Ethylamino)-3-(ethylimino)-
2,7-dimethyl-3H-xanthenyl]benzoate chloride FD-126 Ethyl
-o-[6-(ethylamino)-3-(ethylimino)-
2,7-dimethyl-3H-xanthenyl]benzoate perchlorate FD-127 Ethyl
-o-[6-(ethylamino)-3-(ethylimino)-
2,7-dimethyl-3H-xanthenyl]benzoate tetrafluoroborate FD-128
-o-[6-(Ethylamino)-3-(ethylimino)-2,7-di-
methyl-3H-xanthenyl]benzoic acid FD-129
-o-(6-Amino-3-imino-3H-xanthenyl)benzoic acid hydrochloride FD-130
-o-[6-(Methylamino)-3-methylimino)-3H- xanthen-9-yl]benzoic acid
perchlorate FD-131 Methyl -o-(6-amino-3'-imino-3H-xanthen-
9-yl)benzoate monhydrochloride FD-132
8-(2,4-Disulfophenyl)-2,3,5,6,11,12,-
14,15-1H,4H,10H,13H-otahydroquinolizin-
ol[9,9a,1-bc;9,9a,1-hi]xanthylium hydroxide inner salt FD-133
Sulforhodamine B FD-134 -o-[6-(Dimethylamino)-3-(dimethylamino)-
3H-xanthen-9-yl]benzoic acid perchlorate
______________________________________ PG,38
Another specifically preferred class of xanthene dyes are
fluorescein dyes. Preferred fluorescein dyes are those represented
by Formula XI: ##STR57## where R.sup.10 and R.sup.11 are as
previously defined and
R.sup.20 and R.sup.21 are hydrogen, alkyl, aryl, or halo
substituents. Preferred alkyl groups contain from 1 to 5, optimally
from 1 to 3 carbon atoms while phenyl is a preferred aryl
group.
An illustrative fluorescein dye is
______________________________________ FD-119 9-(
-o-Carboxyphenyl)-6-hydroxy-3H-xanthen- 3-one FD-120 9-(
-o-Carboxyphenyl)-2,7-dichloro-6-hy- droxy-3H-xanthen-3-one
______________________________________
Another useful group of fluorescent dyes are pyrylium,
thiapyrylium, selenapyrylium, and telluropyrylium dyes. Dyes from
the first three of these classes are disclosed by Light U.S. Pat.
No. 3,615,414 while dyes of the latter class are disclosed by Detty
U.S. Pat. No. 4,584,258, the disclosures of which are here
incorporated by reference. Since the latter two classes of dyes are
bathochromically shifted toward the infrared the former two classes
of dyes are preferred for achieving visible light emissions.
Illustrative preferred fluorescent pyrylium and thiapyrylium dyes
are represented by Formula XII: ##STR58## where R.sup.22 is
hydrogen, methyl, or a tertiary amino group, optimally a
--NR.sup.23 R.sup.23 group;
R.sup.23 is an alkyl group;
X.sup.- is an anion; and
J is oxygen or sulfur.
The alkyl group preferably contains from 1 to 5 carbon atoms and
optimally from 1 to 3 carbon atoms. Illustrative pyrylium and
thiapyrylium fluorescent dyes satisfying formula XV are the
following:
______________________________________ FD-135
4-(4-dimethylaminophenyl)-2-(4-methoxy- phenyl)-6-phenylpyrylium
perchlorate FD-136 4,6-diphenyl-2-(4-ethoxyphenyl)thiapyry- lium
-p-toluenesulfonate FD-137 2-(4-methoxyphenyl)-6-phenyl-4-(
-p-tolyl)- pyrylium tetrafluoroborate
______________________________________
Another useful class of fluorescent dyes are fluorescent
carbostyril dyes. These dyes are characterized by a 2-quinolinol or
isoquinolinol ring structure, often fused with other rings. The
wavelengths of maximum fluorescence generally increases with the
presence of other fused rings. Typical of simple carbostyril dyes,
which fluoresce in the blue portion of the spectrum, are the
following:
______________________________________ FD-138
7-Amino-4-methyl-2-quinolinol [a.k.a. 7-amino-4-methylcarbostyril]
FD-139 7-Dimethylamino-2-hydroxy-4-methylquino- line [a.k.a.
7-dimethylamino-4-methylcarbo- styryl] FD-140
3,3'-Bis[N-phenylisoquinoline]
______________________________________
Examples are more complex fused ring carbostyril dyes are provided
by Kadhim and Peters, "New Intermediates and Dyes for Synthetic
Polymer Fibres Substituted Benzimidazolothioxanthenoisoquinolines
for Polyester Fibres", JSDC, Jun. 1974, pp. 199-201, and Arient et
al, "Imidazole Dyes XX-Colouring Properties of
1,2-Napthooxylenebenzimidazole Derivatives", JSDC, Jun. 1968, pp.
246-251. Illustrative of these more complex carbostyril dyes are
the following:
______________________________________ FD-141
Benzimidazo[1,2-b]thioxantheno[2,1,9,- d,e,f]isoquinolin-7-one and
its stereo isomer Benzimidazo[1,2-a]thioxantheno-
[2,1,9,d,e,f]isoquinolin-7-one
______________________________________
Among other fused ring fluorescent dyes the perylene dyes,
characterized by a dinaphthylene nucleus. A variety of useful
fluorescent perylene dyes are known, such as, for example those
disclosed by Rademacher et al, "Soluble Perylene Fluorescent Dyes
with Photostability", Chem. Ber., Vol. 115, pp. 2927-2934, 1982,
and European Patent Application 553,363Al, published Jul. 7, 1982.
One preferred perylene dye is illustrated by Formula XIII:
##STR59## where R.sup.24 and R.sup.25 are independently selected
from the group consisting of alkyl, halo, and haloalkyl
substituents. Preferred alkyl groups having from 1 to 5 carbon
atoms, optimally from 1 to 3 carbon atoms.
Another preferred groups of perylene dyes are the
3,4,9,10-perylenebis(dicarboximides), hereinafter referred to a
perylenebis(dicarboximide) dyes. Preferred dyes of this class are
represented by Formula XIV: ##STR60## where R.sup.26 and R.sup.27
are independently selected from the group consisting of alkyl,
halo, and haloalkyl substituents. Preferred alkyl groups having
from 1 to 5 carbon atoms, optimally from 1 to 3 carbon atoms.
Illustrative of preferred perylene dyes are the following:
______________________________________ FD-142 Perylene FD-143
1,2-Bis(5,6- -o-phenylenenaphthalene) FD-144
N,N'-diphenyl-3,4,9,10-perylenebis(di- carboximide) FD-145 N,N'-di(
-p-tolyl)-3,4,9,10-perylenebis(di- carboximide) FD-146
N,N'-di(2,6-di- .sub.-t-butyl) 3,4,9,10- perylenebis(dicarboximide)
______________________________________
The foregoing listing of preferred fluorescent dyes useful in
combination with the host materials, though lengthy, is recognized
to be only exemplary of known fluorescent dyes, both in the classes
specifically identified and in still other dye classes. For
example, many other classes of known fluorescent dyes, such as
acridine dyes; bis(styryl)benzene dyes; pryrene dyes; oxazine dyes;
and phenyleneoxide dyes, sometimes referred to as POPOP dyes; are
useful, specific illustrative dyes from these classes including the
following:
______________________________________ FD-147 9-Aminoacridine
hydrochloride FD-148 -p-Bis( -o-methylstyryl)benzene FD-149 2,2'-
-p-Phenylenebis(4-methyl-5-phenyl- oxazole) FD-150
5,9-Diaminobenzo[a]phenoxazonium perchlorate FD-151
5-Amino-9-diethylaminobenz[a]phenoxazonium perchlorate FD-152
3,7-Bis(diethylamino)phenoxazonium perchlorate FD-153
3,7-Bis(ethylamino)-2,8-dimethylphenoxa- zin-5-ium perchlorate
FD-154 9-Ethylamino-5-ethylimino-10-methyl-5H-
benzo[a]phenoxazonium perchlorate FD-155
8-Hydroxy-1,3,6-pyrene-trisulfonic acid trisodium salt
______________________________________
Not only are there many available classes of fluorescent dyes to
choose from, there are wide choices of individual dye properties
within any given class. The absorption maxima and reduction
potentials of individual dyes can be varied through the choice of
substituents. As the conjugation forming the chromophore of the dye
is increased the absorption maximum of a dye can be shifted
bathochromically.
Emission maxima are bathochromic to the absorption maxima. Although
the degree of bathochromic shifting can vary as a function of the
dye class, usually the wavelength of maximum emission is from 25 to
125 nm bathochromically shifted as compared to the wavelength of
maximum absorption. Thus, dyes which exhibit absorption maxima in
the near ultraviolet in almost all cases exhibit maximum emissions
in the blue portion of the spectrum. Dyes which exhibit absorption
maxima in the blue portion of the spectrum exhibit emission maxima
in the green portion of the spectrum, and, similarly, dyes with
absorption maxima in the red portion of the spectra tend to exhibit
emission maxima in the near infrared portion of the spectrum.
EXAMPLE 1
Solutions were prepared from Coumarin 314 and Coumarin 314T. Each
was dissolved in EtOH at a concentration of 5.times.10.sup.-3 M to
create reference solutions; in addition, two solutions of each dye
were prepared in water with heptakis
(2,6-di-O-methyl)-.beta.-cyclodextrin. In the absence of
cyclodextrin, neither dye will dissolve in water to any measurable
extent. For each dye, the two cyclodextrin concentrations were
4.5.times.10.sup.-2 M and 9.0.times.10.sup.-2 M; each solution was
saturated with its respective dye and each solution was filtered.
Absorption spectra were run in 1 mm cells and laser output was
measured using an excimer laser pumped dye laser as described in
Chen et al, Applied Optics, Vol. 27, No. 3., p. 443, Feb. 1, 1988.
Results are set forth in the following two tables:
TABLE 1 ______________________________________ Solution Composition
Cyclodextrin Solution No. Dye Solvent Conc'n (in Moles)
______________________________________ 20-1 C-314 EtOH -- 20-2
C-314 H.sub.2 O 4.5 .times. 10.sup.2 20-3 C-314 H.sub.2 O 9.0
.times. 10.sup.-2 20-4 C-314T EtOH -- 20-5 C-314T H.sub.2 O 4.5
.times. 10.sup.-2 20-6 C-314T H.sub.2 O 9.0 .times. 10.sup.-2
______________________________________
TABLE 2 ______________________________________ Absorption
Measurements and Laser Output Laser Output .lambda..sub.max
(Relative Units Solution No. (nm) A.sub. max A.sub.308 nm of
Energy) ______________________________________ 20-1 433.8 2.776
.077 21 20-2 449.8 1.936 .101 10 20-3 445.0 2.988 .158 5 20-4 431.8
2.443 .0345 25 20-5 438.6 1.515 .074 8 20-6 438.4 2.295 .109 4
______________________________________
Coumarin 314 and 314T have the following structural formulas
wherein Me and Et signify methyl, --CH.sub.3, and ethyl, --C.sub.2
H.sub.5, respectively. ##STR61##
EXAMPLE 2
Two experiments were conducted showing that higher concentrations
of substituted cyclodextrin lead to more efficient dye lasing. In
both experiments, Rhodamine 6G in ethanol was used as the standard.
The substituted cyclodextrin was heptakis
2,6-di-O-methyl)-.beta.-clodextrin. The Rhodamine 6G concentration
for all solutions was 4 mM.
The experiments were conducted as generally described in the
previous example. Results are reported in the following Table:
TABLE 3 ______________________________________ Heptakis (2,6-
di-O-methyl)-.beta.- .lambda..sub.max E.sub.out Tuning Range
Solvent cyclodextrin (M) (nm) (.mu.J) (nm)
______________________________________ EtOH -- 578 22.5 556-615
H.sub.2 O 9.3 .times. 10.sup.-3 604 0.78 597-602 H.sub.2 O 3.4
.times. 10.sup.-2 602 2.91 586-614 EtOH -- 578 22.7 554-608 H.sub.2
O 6.9 .times. 10.sup.-1 598 3.73 583-613 H.sub.2 O 1.74 .times.
10.sup.-1 595 9.91 577-614 H.sub.2 O 3.85 .times. 10.sup.-1 588
11.34 575-611 ______________________________________
EXAMPLE 3
Data in the following two tables show the improvement in relative
fluorescence yields for aqueous solutions of dye inclusion
compounds made from substituted .beta.-cyclodextrins, relative to
inclusion compounds prepared from unsubstituted
.beta.-cyclodextrin:
TABLE 4 ______________________________________ Relative
Fluorescence Yields of Three Laser Dyes Included with Various
Substituted .beta.-Cyclodextrins Relative to Inclusion with
.beta.-Cyclodextrin Fluorescence Yields Relative to
.beta.-Cyclodextrin 9-Aminoacridine Rhodamine Hychochloride
Cyclodextrin DASPI 6G 1-Hydrate
______________________________________ .beta.-cyclodextrin 1.00
1.00 1.00 heptakis (2,6-di-O- methyl)-.beta.-cyclodextrin 1.30 1.52
1.45 hydroxypropyl-.beta.- 1.55 cyclodextrin (MS = 0.6)
hydroxypropyl-.beta.- 1.83 1.52 1.23 cyclodextrin (MS = 0.9)
hydroxyethyl-.beta.- 1.20 cyclodextrin (MS = 0.6)
hydroxyethyl-.beta.- 1.42 cyclodextrin (MS = 1.0)
hydroxyethyl-.beta.- 1.51 cyclodextrin (MS = 1.6)
methyl-.beta.-cyclodextrin 1.20 (DS = l.8)
______________________________________
In the table above, MS=molar substitution, which means the number
of indicated groups per anhydroglucose unit in the
.beta.-cyclodextrin ring.
TABLE 5 ______________________________________ Fluorescence Yields
of Various Dyes Included in Heptakis
(2,6-di-O-methy1)-.beta.-Cyclodextrin Relative to Inclusion in
.beta.-Cyclodextrin* Dye Relative Yields
______________________________________ 9-Aminoacridine 1.45
Hydrochloride, 1-Hydrate Carbostyril 165 1.15 Coumarin 6 1.33 DCM
11.0 DODC Iodide 1.13 Oxazine 1 1.20 POPOP 2.02 DASPI 1.30
Rhodamine 6G 1.52 Stilbene 420 1.10
______________________________________ *With two exceptions,
relative yields are based on equal absorption intensities in
cyclodextrin and the substituted cyclodextrin. The two exceptions
are DCM and POPOP for which the listed relative yields are enhanced
by greater water solubility in the presence of heptakis
(2,6di-O-methyl)-cyclo-dextrin.
Dyes used in the above table have the following structural formulas
wherein Me and Et have the significance used above: ##STR62##
Additional results were obtained with a polymeric beta cyclodextrin
purchased from American Tokyo Kasei in Portland, Ore. The supplier
describes the polymer as being soluble in water at least to the
extent of 5 grams per 100 mL, and having an average molecular
weight of 5300. For the experiments reported in the table which
follows, the concentration of dye in the samples tested was
1.times.10.sup.-5, and the concentration of cyclodextrin was 0.20M.
The polymeric cyclodextrin was composed of beta cyclodextrin rings
bridged with groups having the formula CH.sub.2 --CHOH--CH.sub.2
--.
Two other .beta.-cyclodextrin polymers were purchased from FDS
Publications in England and were supplied originally by Chinoin
Pharmaceutical and Chemical Works in Budapest, Hungary. These two
polymers are cross-linked by epichlorohydrin; one of them was
further reacted to add two carboxymethyl substituents per
cyclodextrin ring. In Table 6, the three polymers are designated
#1, #2, and #3 as follows:
Poly-.beta.-cyclodextrin #1 from American Tokyo Kasei
Poly-.beta.-cyclodextrin #2 from Chinoin
Poly-.beta.-cyclodextrin #3 (with carboxymethyl substituents) from
Chinoin.
Polymer #2 has a weight average molecular weight of 4500.
Applicant compared the absorption and fluorescence yield of DASPI
in ethanol, DASPI and .beta.-cyclodextrin in water, and DASPI and
poly-.beta.-cyclodextrin (Polymers 1, 2, and 3 in Table 6) in
water. In each instance, the dye concentration was
5.times.10.sup.-6 molar. The concentration of the
.beta.-cyclodextrin was 0.016 molar, and the concentration of each
polymeric cyclodextrin was 0.020 molar, based on the molecular
weight of the cyclodextrin unit.
Assigning the fluorescence yield of the aqueous .beta.-cyclodextrin
system the value of 1.0, the fluorescence yield of the ethanol
system was 1.5. Surprisingly, with DASPI the fluorescence yield of
each polymer was, as shown by the Table 6, markedly greater than
the fluorescence yield of the dye in ethanol, and also much greater
than the yield for the non-polymeric cyclodextrin.
This level of fluorescence yield increase for an aqueous system
comprising a polymeric, substituted cyclodextrin is apparently
unknown in the art. This discovery comprises a highly preferred
embodiment of this invention.
TABLE 6 ______________________________________ Relative
Fluorescence Levels in Water Measured With .beta.-Cyclodextrin,
Trimethyl-.beta.-Cyclodextrin, and Water-Soluble
.beta.-Cyclodextrin Polymers Dyes Rhodamine 6G DASPI
______________________________________ .beta.-cyclodextrin 1.0 1.0
Heptakis (2,3,6-tri-O- 0.9 0.6 methyl)-.beta.-CD Poly
.beta.-cyclodextrin #1 0.9 3.9 Poly .beta.-cyclodextrin #2 0.9 4.2
Poly .beta.-cyclodextrin #3 0.9 5.1
______________________________________
Similar results are obtained when the polymer employed in the
Examples reported in Table 6 are replaced with other polymers
having .alpha. or .beta. cyclodextrin rings bridged by groups
having the formula CHR.sup.1 --CHOH--CHR.sup.1, wherein R.sup.1 is
selected from hydrogen and alkyl groups having up to six carbon
atoms, such that the number of cyclodextrin rings so bridged is
from two to about six.
The invention has been described above in detail with particular
reference to preferred embodiments. A skilled practitioner,
familiar with the above-detailed description, can make many
modifications and substitutions without departing from the spirit
and cope of the appended claims.
* * * * *